The present invention relates to the physical separation of a multiphase stream into its component phases. More particularly, the invention relates to a housing for a sheet of phase-separating material.
It is frequently important during the filtration of a fluid to bring the fluid into intimate contact with the surface of the filter medium. This is particularly true when a membrane separator is employed. A membrane separator can function in a manner that filters out particulates, separates liquids from gases, and in some cases separates immiscible liquids from one another.
Under any circumstances it is always very important that the fluid contact the entire available surface of the filter medium or the membrane. A common technique employed, particularly in analytical applications, is to have the fluid enter a housing, and have a portion of the fluid entering the housing bypass the filter medium. This procedure is followed in order to decrease the transport time, and to purge incoming sample lines. This procedure also serves in many cases to remove some of the materials that were separated from the incoming fluid by the filter medium. This is particularly so in membrane separators in which liquids are rejected by the membrane and are swept out with the bypass stream.
It is also possible to remove particulates continuously as they accumulate on the surface of the filter medium or membrane. The filtrate leaves the housing through an outlet port. In the case of analyzers, the sample is taken through perhaps further conditioning before being sent to an analyzer.
It is very important, particularly when particles accumulate on the surface of the membrane or filter medium, to have a high velocity of the fluid perpendicular to the surface of the membrane or filter medium, in order to remove particles that might accumulate thereon. There are in the prior art filtration devices which attempt to accomplish this objective by bringing the fluid sample into an inlet of a housing tangentially, thereby giving the fluid a centrifugal or swirling motion that is perpendicular to the filter medium or membrane. The problem with this approach is that there is no assurance that the fluid is effectively shearing across the entire surface of the membrane or filter medium.
There are other instances in which the objective of bringing the fluid into a membrane separator housing is to separate liquids from an entrained gas, or to separate immiscible liquids, or to recover a gas that is dissolved or dispersed in the incoming liquid. In all of these cases, it is also very important that the entire membrane area be exposed to the fluid sample, and conversely that the entire fluid sample be exposed to the surface of the membrane to ensure, particularly in the case of a gas dispersed or dissolved in a liquid, that all of the fluid contact the membrane, in order that the gas pass through the membrane and thereby become separated from the liquid phase. After the liquid contacts the membrane, it is usually rejected and vented.